Barbecue grills are in popular use for outdoor home cooking and for commercial use. Many grills today use a metal grate interposed between the burner and the cooking surface to replace charcoal or stones, to heat food more evenly, and to vaporize grease drippings. Some examples of grills in the prior art are seen in the following U.S. patents:
Barker, U.S. Pat. No. 5,279,277, shows a curved, one-piece grate. No holes are provided for convection through the grate. The food cooks by heat radiated from the grate. Grease drips upon the grate and is vaporized. Minimal venting is provided for the escape of combustion gases.
Holland, U.S. Pat. No. 5,313,877, illustrates a one-piece grate with no holes in the grate. Holes are located in the housing around the periphery of the grate, to provide convection flow of hot gases to the space above the food. The grate includes a trough and drain pipe to drain grease to an external container.
McLane, U.S. Pat. No. 4,878,477, and Peterson, U.S. Pat. No. 5,582,094, both disclose a corrugated cooking surface with multiple holes for convection flow, and to drain grease to a collection point.
McLane, Sr., U.S. Pat. No. 4,762,059, shows multiple-piece V-shaped grate members for collecting grease drippings and evaporating them. Large holes are provided for convection flow.
Harris, U.S. Pat. No. 5,121,738, discloses a grate formed of a plurality of ceramic briquettes configured to catch and vaporize grease. Space is provided around the periphery of the grate for convection flow of hot gases.
Doolittle, U.S. Pat. No. 5,165,385, illustrates a conventional multiple rod grid type of grate for supporting charcoal or stone briquettes. Large holes allow generous convection flow.
While the above-described grills are functional for cooking food, they all display shortcomings inherent in their design. Grates made of stainless steel, or other non-heat resistant materials will burn out quickly from the heat of the flame. Grills with large holes in or surrounding the grate allow hot combustion gases to flow by convection through the grate. The hot gases are intended to cook the food. However, there is evidence that products of combustion, when introduced to food during cooking, may form carcinogens on the food. A one-piece fire grate would prevent convection flow of gases through the grate and around the food. Furthermore, as the gases flow out of the combustion space, cold ambient air flows into the space to displace the exiting gases. The cold air cools the system, resulting in long heat-up times and cooler cooking temperatures. Flowing gases tend to form eddy currents in pockets and corners of the combustion space, causing uneven temperature distribution on the grate, and consequent uneven cooking of the food. The curved grate of Barker, for example, will exhibit different temperatures at the edges than at the center. The flat or curved grates radiate heat substantially in one direction, upward. A corrugated grate, having ridges and valleys, will distribute heat more evenly over the grill area than a flat or curved grate. A corrugated grate will also radiate heat sideways as well as upward, to cook the food from the side as well as from below. Multiple-piece grates are expensive to fabricate and difficult to clean. A one-piece grate such as that of Barker has no hole for visual confirmation of flame ignition, leading to a dangerous situation in which unignited gas can collect in the combustion space. Provision should be made to operate the grill with charcoal briquettes or without briquettes, as desired. None of the prior art grills provide this option. Grates that drain grease to an external collection point are messy and are subject to fires in the drainage system, and congealing of grease when the system cools down. Grills equipped with two or more burners can be used with one burner for economy. However, some means, such as a wall, must be provided for confining the heat to that part of the grate which is in use. None of the above-described grills have this provision.
Accordingly, there is a need to provide a barbecue grill having a heat-resistant metal fire grate to vaporize grease for a cleaner barbecue, without burning out the grate;
there is another need to provide a barbecue grill fire grate of the type described, and having one-piece construction for simplicity and economy;
there is yet another need to provide a barbecue grill fire grate of the type described, and having no holes large enough for any significant convection current flow through the grate, so that the food will cook by radiant heat only, excessive cold air flow will not cool the grill, and products of combustion will not form carcinogens on the food;
there is a still another need to provide a barbecue grill fire grate of the type described, and having a small hole for visual confirmation of flame ignition;
there is a further need to provide a barbecue grill fire grate of the type described, and having a corrugated shape to distribute heat evenly and to radiate heat to the food from several different directions;
there is a still further need to provide a barbecue grill fire grate of the type described, and having a divider wall for use with one burner to conserve fuel;
there is a yet further need to provide a barbecue grill fire grate of the type described, and that provides the option of cooking with or without charcoal briquettes; and
there is an additional need to provide a barbecue grill fire grate of the type described, and that can be manufactured economically in large quantities of high quality, and that will have a long service life.